The result is:

This page shows how to draw multiple axhlines and axvlines in one function using python and matplotlib.

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In [1]:

import platform
print('python: '+platform.python_version())
import matplotlib.pyplot as plt
from matplotlib import __version__ as matplotlibversion
print('matplotlib: '+matplotlibversion)
import numpy as np
print('numpy: '+np.__version__)
pi = np.pi

python: 3.7.6
matplotlib: 3.1.3
numpy: 1.18.1

In [2]:

# sine and cosine dummy curve data to plot
xx  = np.linspace(0, 3.*pi)
yy1 = np.sin(xx)
yy2 = np.cos(xx)

Define axvlines and axhlines functions to plot multiple v-line(s) and h-line(s), respectively.

In [3]:

def axvlines(ax=None, xs=[0, 1], ymin=0, ymax=1, **kwargs):
    ax = ax or plt.gca()
    for x in xs:
        ax.axvline(x, ymin=ymin, ymax=ymax, **kwargs)

def axhlines(ax=None, ys=[0, 1], xmin=0, xmax=1, **kwargs):
    ax = ax or plt.gca()
    for y in ys:
        ax.axhline(y, xmin=xmin, xmax=xmax, **kwargs)

Keyward argments can be also used in above function as follows.

In [4]:

fig = plt.figure()
ax1 = fig.add_subplot(2, 1, 1)
ax2 = fig.add_subplot(2, 1, 2, sharex=ax1)
ax1.plot(xx, yy1, c='b')
ax2.plot(xx, yy2, c='b')
axvlines(ax=ax1, xs=[0.0*pi, 1.0*pi, 2.0*pi], c='r', ls='--')
axvlines(ax=ax2, xs=[0.5*pi, 1.5*pi, 2.5*pi], c='g', ls='-.')
axhlines(ax=ax1, ys=[-1.0, 0.0, 1.0], c='k', lw=0.5)
axhlines(ax=ax2, ys=[-1.0, 0.0, 1.0], c='k', lw=0.5)
plt.savefig('ax_vh_lines.png', bbox_inches='tight', pad_inches=0.02)

Draw multiple axhlines and axvlines in one function using Python & Matplotlib